(a) Field of the invention
The present invention relates to a compact retrofocus type lens system.
(b) Description of the prior art
Among the conventional retrofocus lens systems of the type as disclosed in the specification of Japanese Published Examined Patent Application No. 2371/76 (a corresponding patent being U.S. Pat. No. 3,832,037), there are ones in which the peripheral resolution is not satisfactory. The increase of the lateral chromatic aberration at the peripheral portions is the main cause of such an unsatisfactory peripheral resolution. For example, the lateral chromatic aberrations of the embodiments 1 and 2 given in the above identified publication are shown in FIG. 4 and FIG. 5, respectively. Thus, when the lateral chromatic aberration is large, the image at the peripheral portions is blurred. Unlike the blur of the image caused by the coma, the problem in the blur of the image mentioned above is not resolved even by making the aperture smaller.